Apparatus of inspecting defect in semiconductor and method of the same

ABSTRACT

When size of a defect on an increasingly miniaturized pattern is obtained by defect inspection apparatus in the related art, a value is inconveniently given, which is different from a measured value of the same defect by SEM. Thus, a dimension value of a defect detected by defect inspection apparatus needs to be accurately calculated to be approximated to a value measured by SEM. To this end, size of the defect detected by the defect inspection apparatus is corrected depending on feature quantity or type of the defect, thereby defect size can be accurately calculated.

CROSS REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. patent application Ser. No.12/349,373, filed Jan. 6, 2009, which is a Continuation of U.S. patentapplication Ser. No. 11/488,622, filed Jul. 19, 2006, now U.S. Pat. No.7,474,394, which claims priority from Japanese Patent Application No.2005-209384, filed in Japan on Jul. 20, 2005, the contents of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to defect inspection apparatus and adefect inspection method which are used in a manufacturing line of asemiconductor device, liquid crystal device, magnetic head or the like,and particularly relates to a calculation technique of size of adetected defect.

Inspection of a semiconductor wafer is described as an example.

In a semiconductor manufacturing process in the related art, foreignsubstances on a semiconductor substrate (wafer) may cause inferioritysuch as imperfect insulation or a short circuit. When a fine foreignsubstance exists in a semiconductor substrate of a semiconductor elementwhich is significantly miniaturized, the foreign substance may causeimperfect insulation of a capacitor or breakdown of a gate oxide film.The foreign substances may be contaminated in various ways due tovarious reasons, such as contamination from a movable portion of acarrier device, contamination from a human body, contamination fromreaction of a process gas in treatment equipment, and previouscontamination in chemicals or materials. Similarly, in a manufacturingprocess of a liquid crystal display device, contamination of a foreignsubstance on a pattern, or formation of some defects disables the deviceas a display device. The same situation occurs in a manufacturingprocess of a printed circuit board, that is, contamination of theforeign substance leads to a short circuit of a pattern or imperfectconnection.

It is now increasingly important to detect a defect such as foreignsubstance causing inferior products and take the measure for causes ofthe defect and thus keep a certain yield of products for stablyproducing a semiconductor element or a flat display device representedby the liquid crystal display device, which are expected to be furtherminiaturized even more in the future.

To keep the yield of products, it is necessary to determine whether adetected defect such as foreign substance has influence on the yield ornot, and it is important to obtain information of a position where thedefect such as foreign substance was detected, and information of sizeof the detected defect.

As a technique for calculating size of a defect detected by defectinspection apparatus, as described in JP-A-5-273110, a method isdisclosed, in which a laser beam is irradiated to an object, and thenscattering light from a particle on the object or a crystal defecttherein is received and then subjected to image processing, thereby sizeof the particle or the crystal defect is measured. In “Yield Monitoringand Analysis in Semiconductor Manufacturing” mentioned in digest of ULSItechnical seminar, pp 4-42 to 4-47 in SEMIKON Kansai in 1997, a yieldanalysis method using a defect by a foreign substance detected on asemiconductor wafer is disclosed.

SUMMARY OF THE INVENTION

As described above, inspection apparatus in the related art for variousfine patterns including a pattern in a semiconductor device is now hardto satisfy detection accuracy of defect size required for detection of adefect on an increasingly miniaturized pattern. Therefore, it isdesirable to accurately calculate size of a detected defect.

Defect inspection apparatus according to embodiments of the inventionincludes a unit for classifying defects into a plurality of classesbased on feature quantity of the defects at detection, and modifying asize calculation method of a defect for each of classes.

That is, in embodiments of the invention, defect detection apparatus fordetecting a defect of an object is configured to have an illuminationunit for illuminating light to the object; a detection unit fordetecting scattering light from the object; a defect detection unit fordetecting the defect by processing a detection signal of the scatteringlight detected by the detection unit; a size measuring unit forcalculating size of the defect detected by the defect detection unit; asize correction unit for correcting the size of the defect detected bythe size measuring unit depending on separately obtained information offeature quantity or a type of the defect; a data processing unit forprocessing a result corrected by the size correction unit; and a displayunit for displaying information of a result processed by the dataprocessing unit.

According to embodiments of the invention, size of a detected defect canbe accurately calculated, and for example, only defects having a sizelarger than a size to be managed can be extracted in semiconductormanufacturing. Thus, since a defect having higher influence on aproduction yield can be preferentially managed, productivity is improvedin semiconductor manufacturing.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, features and advantages of the invention willbe apparent from the following more particular description of preferredembodiments of the invention, as illustrated in the accompanyingdrawings.

FIG. 1 is a block diagram showing a schematic configuration of defectinspection apparatus according to embodiments of the invention;

FIGS. 2A to 2B are graphs showing examples of defect detection signals,wherein FIG. 2A shows a case of large signal intensity, and FIG. 2Bshows a case of small signal intensity;

FIGS. 3A to 3B are views showing processing for each region, whereinFIG. 3A shows an example of dividing the inside of a die (chip), andFIG. 3B shows an example of dividing a front face of a wafer;

FIGS. 4A to 4B are scatter diagrams of defect size, wherein FIG. 4Ashows an example of large dispersion, and FIG. 4B shows an example ofsmall dispersion;

FIGS. 5A to 5B are views showing examples of representative values ofdefect size, wherein FIG. 5A shows an example of X or Y size, and FIG.5B shows an example of L size;

FIG. 6 is a flowchart of setting a correction factor of sizecalculation;

FIG. 7 is a flowchart of inspection and output;

FIGS. 8A to 8C are views showing examples of size correction usingdefects of which the size is known, wherein FIG. 8A shows a conditionthat the defects of which the size is known are disposed on a wafer,FIG. 8B shows a condition that size measured by SEM does notcomparatively correspond to size detected and calculated by the defectinspection apparatus in a scatter diagram of defect size, and FIG. 8Cshows a condition that the calculated size comparatively corresponds tothe size measured by SEM by changing a slope of a graph by changing afactor when size of a defect detected by the defect inspection apparatusis calculated, in the scatter diagram of defect size;

FIG. 9 is a flowchart of calculating a correction factor of size;

FIGS. 10A to 10C are views showing correction examples when a defectsignal is saturated, wherein FIG. 10A is a graph showing a conditionthat the defect signal is not saturated, FIG. 10B is a graph showing acondition that the defect signal is saturated, and FIG. 10C is a viewshowing a method of predicting a peak value of a signal when a detectionsignal is saturated;

FIGS. 11A to 11B are scatter diagrams of defect size, wherein FIG. 11Ashows a condition that size measured by SEM does not comparativelycorrespond to size detected and calculated by the defect inspectionapparatus, and FIG. 11B shows a condition that size, which wascalculated with performing correction to a defect detected by the defectinspection apparatus based on feature quantity of the defect,comparatively corresponds to the value measured by SEM;

FIG. 12 is a block diagram showing a relationship between amanufacturing process and inspection apparatus;

FIG. 13 is a graph showing a relationship between yield and the numberof detected defects;

FIGS. 14A to 14B are graphs showing examples of a method of extracting adefect signal and feature quantity, wherein FIG. 14A shows a case ofusing a threshold obtained by a normal threshold setting method, andFIG. 14B shows a case of setting a threshold lower than a normalthreshold;

FIG. 15 is a front view of a display screen showing a screen displayexample of the defect inspection apparatus; and

FIGS. 16A to 16B are view of an example of an illumination opticalsystem, wherein FIG. 16A is a front view, and FIG. 16B is a side view.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows an example of a configuration of inspection apparatusaccording to embodiments of the invention (hereinafter, mentioned asdefect inspection apparatus).

The defect inspection apparatus is configured to have an illuminationsystem 100, a stage system 200, a detection system 300, a Fouriertransform surface observation system 500, a signal processing section400, an observation optical system 600, and a control section 2.

Defect detection using the defect inspection apparatus shown in FIG. 1is performed according to the following procedure. The illuminationsystem 100 illuminates a wafer 1 set in the stage system 200, and thedetection system 300 acquires an image of the illuminated wafer 1. Theillumination system 100 adjusts output of a light source 101 by anillumination controller 103 according to an instruction value of thecontrol section 2. As the light source 101, a laser light source isused, which emits laser in an ultraviolet region having a wavelength of400 nm or less. The illumination system 100 includes a unit (not shown)for reducing coherency of the laser emitted from the laser light source.Illumination light is shaped into an appropriate form on the wafer 1 byan optical system 102. The stage system 200 includes a rotation stage201, a Z stage 202, an X stage 203, and a Y stage 204, and moves withrespect to the detection system 300 so that the detection system 300 canscan the whole surface of the wafer 1.

The detection system 300 includes a Fourier transform lens 301, spatialfilter 302, focusing lens 303, and sensor 304. Here, the spatial filter302 is to shield a diffraction light pattern caused by diffraction lightfrom a repetitive pattern on the wafer 1, and set on the Fouriertransform surface of the Fourier transform lens 301.

A light shielding pattern of the spatial filter 302 is set such that adiffraction pattern of the wafer 1 is shielded, the diffraction patternbeing observed by the Fourier transform surface observation system 500having a structure that can be inserted and removed into/from an opticalpath of the detection system 300. That is, the system 500 is insertedinto an optical path of the detection system 300 while removing thespatial filter 302, and then the optical path is branched by a beamsplitter 501, and an image on the Fourier transform surface of theFourier transform lens 301 is taken by a camera 503 via a lens 502 andobserved. The light shielding pattern of the spatial filter 302 can beset for each type of an object or each of steps. The light shieldingpattern of the spatial filter 302 may be fixed during wafer scan, or maybe changed in real time depending on a region under scanning.

An image acquired by the detection system 300 is subjected to ADconversion and then transferred to the signal processing section 400,wherein the image is processed to detect a defect. The defect inspectionapparatus further includes CPU 2, a display device 3, an input unit 4,and a storage device 5, thereby it can set any optional condition forinspection, and can store and display an inspection result or aninspection condition. Moreover, the defect inspection apparatus can beconnected to a network 6, thereby the inspection result, layoutinformation of the wafer 1, a lot number, the inspection condition, oran image of a defect observed by an observation device or data of adefect type can be shared over the network 6. Moreover, the defectinspection apparatus includes the wafer observation system 600 in orderto allow observation of the detected defect or an alignment markintegrally formed on the wafer 1 for alignment of a pattern formed onthe wafer 1. Furthermore, while not shown, it includes an automaticfocusing unit, so that a region where an image is taken in using asensor when the wafer is scanned on the stage system 200 is within thedepth of focus of the detection system 300.

FIGS. 2A to 2B show three-dimensional display of examples of signaldetection of two types of defects A and B respectively. FIGS. 2A to 2Bexemplify defects having different signal intensity detected by thedefect inspection apparatus while having the same size. A verticaldirection represents signal intensity, showing intensity for each pixel.Even if defects (foreign substances) have the same size in SEM (scanningelectron microscope) observation, detection signals in the defectinspection apparatus may be varied depending on a defect type, defectposition, and surface pattern or surface material of the wafer 1. Thus,size of defects obtained through detection by the defect inspectionapparatus according to embodiments of the invention are corrected basedon information of the defect type, defect position, and surface patternor surface material of the wafer 1, thereby size calculation accuracy ofdefects can be improved.

Moreover, to improve the size calculation accuracy of a defect, it isimportant to modify a detection condition depending on a position of thedefect. Thus, in the defect inspection apparatus according toembodiments of the invention, grouping is carried out depending onfineness of a pattern in a detection portion of the wafer 1 or each ofmany dies (chips) formed on the wafer 1, so that a detection conditionof the defect can be modified.

FIGS. 3A to 3B show examples of grouping for each of regions in thewafer or die (chip). FIG. 3A shows an example of grouping the inside ofthe die depending on a type of a circuit pattern. A reference 3001 showsa region where a wiring pattern is random in the die, and a reference3002 shows a region where the wiring pattern is repeated at a constantpitch. FIG. 3B shows an example of grouping of the whole surface of thewafer 1. A reference 3003 indicates a central portion of the wafer 1,and a reference 3004 indicates the outer circumferential portion of thewafer. A reference 3005 indicates a die. In the case of a fine pattern,interference of illumination light may occur due to a pattern near adefect and the defect, and thus a detection signal of a defect may bedifferent from that in the case of detecting a defect near a coarsepattern, and therefore grouping is carried out depending on regions.Moreover, when thickness is uneven in a wafer surface due to deposition,etching, or polishing, since a detection signal of a defect may bevaried due to interference of light as well, grouping is carried out.

FIGS. 4A to 4B show an evaluation method of dimension accuracy of adefect. A graph is displayed on a screen, in which measured values ofsize by defect observation apparatus such as SEM are plotted as ahorizontal axis, and calculated values of size by the defect inspectionapparatus are plotted as a vertical axis, which allows visual expressionof calculation accuracy of defect size. FIG. 4A shows an example oflarge dispersion of defect distribution, that is, low dimensionaccuracy. FIG. 4B shows an example of small dispersion of defectdistribution compared with the example of FIG. 4A, that is, highdimension accuracy.

FIGS. 5A to 5B are views for illustrating a way of defining a measuredvalue when defect size is measured by the defect observation device suchas SEM. X and Y are coordinate axes used in observation of a defect bySEM. In a way of expressing the defect size, projected length in anX-axis direction (X size), projected length in an Y-axis direction (Ysize), diameter of a circumscribed circle of a defect (L; major axissize), √(X+Y), or √(X²+Y²) can be used as a representative value. Inyield management, one of the diameter of the circumscribed circle of thedefect (L; major axis size), √(X+Y), and √(X²+Y²), or a combination ofthem is used.

FIG. 6 shows a condition setting flow for correcting size of a defectdetected by the defect inspection apparatus. In embodiments of theinvention, a correction factor that was determined and stored accordingto the flow of FIG. 6 is used, and size of a defect on the wafer, whichwas inspected and detected by the defect inspection apparatus accordingto a flow shown in FIG. 7, is calculated, and then inspection data addedwith size is registered into a defect management server.

A flow of FIG. 6 is described below. Inspection is performed using thedefect inspection apparatus in S601, and defects to be observed by thedefect observation apparatus such as SEM are selected from defectsdetected using the defect inspection apparatus in S602. When the numberof defects is small, for example, about 100, the whole number of themmay be selected. When the number of defects is large, while they may berandomly extracted, if defects to be observed are extracted using SSA(Spatial Signature Analysis) based on a distribution condition in awafer plane, several types of defects in a wafer can be evenlyextracted. After defects as objects are selected in S602, size or a type(convex defect, concave defect, planar defect or the like) of the defectas object selected by the defect observation apparatus such as SEM isobtained in S603. After that, based on information of the size or typeof the defect, a size calculation result of the defect inspectionapparatus is compared with a measurement result of the defectobservation apparatus such as SEM to create a scatter diagram as shownin FIG. 4 in S604, then a correction factor is determined depending onthe size or type of the defects in S605, and then stored in S606.

Comparison between the size calculation result of the defect inspectionapparatus and the measurement result of the defect observation apparatussuch as SEM in S604 can be carried out by the defect inspectionapparatus, SEM, a separated personal computer or the like. Sincecreation of the scatter diagram in S604 is intended to be for referencewhen a user adjusts a condition, in the case that the correction factoris automatically calculated, it need not always be showndiagrammatically. In correction in S605, linear correction (y=ax+b): (xis defect size calculated by the defect inspection apparatus, y is sizeafter correction, a is a correction factor, and b is an offset value)may be used, or a higher-order transformation equation may be used forthe correction. Regarding a way of determining the correction factor aor the offset value b, one of a value previously registered into thedefect inspection apparatus, a value adapted for each treatment step inwafer manufacturing, and a value corresponding to a defect type orfeature quantity of a defect, or a combination of them may be used.

After the correction factor has been calculated in S605, the correctionfactor is stored in S606, consequently condition setting for sizecalculation is completed.

FIG. 7 shows a flow of inspection and output. A wafer is inspected(S701), then classification of defects is performed based on a defecttype or feature quantity of a defect (S702). Defect size is calculatedin S703, and then size is corrected for each defect class using thecorrection factor previously set according to the flow described usingFIG. 6 in S704. A size calculation result S705 after correction is addedto the defect detection result, then data of them are transferred to adefect management server (S706).

FIGS. 8A to 8C show a method of size calibration using a defect havingknown size. FIG. 8A shows a standard wafer in which the defects havingknown size are integrally formed, or a product wafer, dummy wafer, ormirror wafer on which standard particles are scattered, wherein defects901 (size A (nm)), 902 (size B (nm)), and 903 (size C (nm)) having knownsize are integrally formed.

FIG. 8B shows an aspect that the size detected and calculated by thedefect detection apparatus is different from the size measured by SEMdepending on a surface condition or surface material of a wafer due toan adjustment condition of the defect detection apparatus or differencein machine, indicating a relationship between actual size of the defects901, 902 and 903 having known size, which were measured using SEM, andsize of the defects detected and calculated by the defect detectionapparatus. A reference 904 indicates an approximate curve. Based on theapproximate curve of 904, a factor in size calculation is changed sothat a slope of a graph is corrected to be approximately 45 degrees(FIG. 8C), thereby a value of the defect size detected and calculated bythe defect detection apparatus can be calibrated.

FIG. 9 shows a flow of obtaining a factor for correcting size. First, awafer is inspected to detect a defect using the defect inspectionapparatus according to embodiments of the invention (S901), then a sumsignal of detection signals in the whole region of the detected defectis calculated (S902). Since part of the detected defects may be beyond adynamic range of the sensor 304, saturating signal correction (S903) isperformed, and size is temporarily calculated (S904). In this timepoint, since the calculated size may be different from actual sizemeasured by SEM, an approximate formula is then calculated (S905), andthen a correction factor is calculated according to the approximateformula (S906). For correction, linear correction (y=ax+b): (x is defectsize calculated by the defect inspection apparatus, y is size aftercorrection, a is a correction factor, and b is an offset value) may beused, or a higher-order transformation equation may be used.

FIGS. 10A to 10C show a specific example of the saturating signalcorrection of the step S903 in FIG. 9. FIG. 10A shows an example of adefect of which the signal is not saturated, wherein d01 indicates asignal peak. FIG. 10B shows signal intensity (d02) of a defect of whichthe signal is partially beyond a dynamic range of a sensor duringdetection of a defect signal and thus saturated. As shown in FIG. 10C, aportion where a defect signal is lacked because of saturation isapproximated by an appropriate function, so that a signal of a lackedportion is estimated, thereby a saturating signal can be corrected. Forexample, when a defect signal is approximated by Gaussian curve, a valueof the number of saturated pixels (d03) and broadening of Gaussiandistribution (standard deviation) are supposed, thereby a peak (d04) ofthe defect signal can be estimated.

FIGS. 11A to 11B show correction based on feature quantity of a defect.A correction factor is obtained according to a procedure shown in FIG. 6for each defect type (convex defect, concave defect, planar defect orthe like), then a correction factor of defect size is modified based onfeature quantity of a defect according to a procedure of FIG. 7, therebydimension accuracy can be improved. FIG. 11A is a scatter diagram ofdefect size, showing a condition that size measured by SEM does notcomparatively correspond to size detected and calculated by the defectinspection apparatus. On the contrary, FIG. 11B is a scatter diagram ofdefect size in a condition that size, which was calculated withperforming correction based on feature quantity of a defect (forexample, defect size) to a defect defected by the defect inspectionapparatus, comparatively corresponds to size measured by SEM. Size maybe calculated by obtaining the correction factor for each defect type(convex defect, concave defect, planar defect or the like), rather thanthe feature quantity of a defect.

While a procedure of temporarily obtaining size before correction isshown here, size may be calculated at a time during size calculationusing information such as feature quantity of a defect or the defecttype. For this purpose, information on defects such as feature quantityof a defect or a defect type can be treated as a variable in a sizecalculation formula in size calculation.

FIG. 12 shows a relationship between the defect inspection apparatusaccording to embodiments of the invention and a semiconductormanufacturing process. A wafer after passing through a particular stepis inspected by the defect inspection apparatus according to embodimentsof the invention. In a manufacturing process 810, for example,inspection is carried out after a photolithography step (810). After theinspection, a defect is observed by review apparatus 1001 or 1002, sothat a cause of the defect is estimated from a type, size, or a shape ofthe defect to find a step where the defect is caused, thereby amanufacturing device in the relevant step is managed. When the cause ofthe defect is not found only by defect observation, element analysis byan analyzer 1003 or observation of a section profile of the defect isperformed for further detailed investigation to search the cause of thedefect. As described above, a yield of the semiconductor device isimproved by repeating inspection and measures, consequently reliablesemiconductor device can be manufactured.

FIG. 13 shows a relation between the number of defects and a yield of asemiconductor product. A reference 906 indicates transition of the yieldof the semiconductor product, a reference 907 indicates transition oftotal detection number of defects in a particular step. A reference 908indicates transition of the number of a particular type of defects (inthis case, short-circuit defect). While the yield 906 is significantlydecreased in a hatched period in FIG. 13, the total detection number 907is increased only slightly. When the detected defects are classified,and the number of short-circuit defects is noticed, it is known that theshort-circuit defects are increased in the period where the yield isdecreased. In addition to the total number of defects, defects areclassified, and the number is monitored for each defect type, therebyinformation in correlation with the yield of the semiconductor productcan be obtained. The number of defects of which the size is at leastmanagement size may be noticed and managed by using a defect sizecalculation value rather than the defect type. The management size isdetermined based on a wiring rule in an inspection step. While notshown, criticality of the defect may be calculated from the defect size,defect type, and wiring rule to monitor the number of defects having atleast a certain value of criticality.

FIGS. 14A to 14B are conceptual diagrams of defect detection thresholdsT01, T02 and a feature-quantity extraction threshold T03. FIG. 14A showsan example where the defect detection threshold T01 is equal to thefeature-quantity extraction threshold T03. In inspection of asemiconductor wafer, the defect detection threshold T01 is normally sethigh to suppress false detection of a normal portion. Therefore, in FIG.14A, only a part of defect signals can be used. Thus, as shown in FIG.14B, the feature quantity is extracted with a threshold (T04) lower thanthe defect detection threshold T02, thereby more effective extraction ofthe feature quantity can be performed.

FIG. 15 shows a display example of a defect detection result. Areference 801 indicates an example of a display screen. In a defect map(802), display is classified depending on whether defect size is atleast a defect management size determined at setting of inspectionconditions or not, thereby trouble occurrence and a level of influenceon the yield can be instinctively determined. Moreover, defect displayis clicked by a mouse, thereby defect ID, size (calculation value of thedefect inspection apparatus), a defect type and the like can be shown(803).

Moreover, a graph showing frequency of defect occurrence is displayedfor each defect size (807), thereby the trouble occurrence and the levelof influence on the yield can be also instinctively determined.

On the screen, a region 804 for displaying the total number of detecteddefects or the number of the defects for each size, a region 805 fordisplaying an operational panel, a region 806 for setting a inspectioncondition, a region 808 for displaying a defect list are also provided.The display regions may be displayed on one screen at the same time, ormay be displayed on separated screens respectively, or several regionsof them may be displayed in a combined manner.

FIG. 16 shows an example of the illumination optical system 102 in theconfiguration of the defect inspection apparatus shown in FIG. 1. Here,an example where the light source 101 is a laser light source is shown.Laser 1011 emitted from the laser light source 101 is diverged at acertain divergence angle, and made into parallel light by a lens 1021,and then shaped to be one-sided condensing illumination by a cylindricallens 1022 and then irradiated to a wafer surface. An illuminationpattern is linear on the wafer surface, and used in a combined mannerwith scan of the stage, thereby a certain area of the wafer surface canbe collectively detected. In this case, for the sensor 304, a linearsensor corresponding to the illumination area or a TDI sensor (TimeDelay Integration Sensor) is preferably used. When the TDI sensor isused for the sensor 304, a signal detected by the TDI sensor isoutputted in parallel from a plurality of taps of the TDI sensor, andthe signals outputted in parallel are subjected to signal processing inparallel in the signal processing section 400, thereby defect detectionspeed can be improved. When the illumination pattern is a dot-likepattern, AOM, AOD, a galvanometer mirror or the like is used in theillumination optical system to allow scan by the dot-like illumination,and movement of the stage is combined therewith, thereby the wholesurface of the wafer can be inspected.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description and all changeswhich come within the meaning and range of equivalency of the claims aretherefore intended to be embraced therein.

1. A defect inspection apparatus comprising: an illumination unit forilluminating light to an object to be inspected, a detection unit fordetecting scattered light from the object to be inspected, a signalprocessing unit for detecting a defect by processing a detection signalof the scattered light detected by the detection unit, calculating sizeof the defect detected by the defect detection unit, and calibrating thesize of the defect calculated by the calculating, by using arelationship between a size of a defect whose size is known and a sizeof the defect calculated.
 2. The defect inspection apparatus accordingto claim 1: wherein the illumination unit obliquely irradiates linearlyshaped light to a surface of the object to be inspected.
 3. The defectinspection apparatus according to claim 1: wherein the illumination unitirradiates laser having a wavelength of less than 400 nm to the objectto be inspected.
 4. The defect inspection apparatus according to claim1: wherein the detection unit includes a spatial filter for shieldingscattered light from a repetitive pattern formed on the object to beinspected in the scattered light from the object to be inspected, and asensor for detecting scattered light which was not shielded by thespatial filter.
 5. The defect inspection apparatus according to claim 1:further comprising a display unit for displaying positional informationand size of a defect, a defect type, and criticality as the informationof the result processed by the data processing unit.
 6. The defectinspection apparatus according to claim 1: wherein the light detectionunit includes a TDI sensor that outputs detection signals in parallel,and the defect detection unit processes the signals outputted inparallel from the TDI sensor in parallel.
 7. A defect inspection methodcomprising steps of: illuminating light to an object to be inspected,detecting light scattered from the object to be inspected due toirradiation of the light, detecting a defect by processing a detectionsignal of the scattered light, calculating size of the detected defect,and calibrating the size of the defect calculated, by using arelationship between a size of a defect whose size is known and a sizeof the defect calculated.
 8. The defect inspection method according toclaim 7: wherein in the step of illuminating light to the object to beinspected, said light is shaped linearly and is obliquely irradiated toa surface of the object to be inspected.
 9. The defect inspection methodaccording to claim 7: wherein in the step of illuminating light to theobject to be inspected, said light is a laser having a wavelength ofless than 400 nm.
 10. The defect inspection method according to claim 7:wherein in the step of detecting light scattered from the object, lightscattered from repetitive patterns formed on the object is shielded by aspatial filter, and light scattered from the object and not shielded bythe spatial filter is detected by a sensor.
 11. The defect inspectionmethod according to claim 7: further comprising a step of displayinginformation on positional data and size of a defect, a defect type, andcriticality as the information of the processed result.
 12. The defectinspection method according to claim 7: wherein in the step of detectingthe scattering light, the scattered light is detected by a TDI sensorthat outputs detection signals in parallel, and in the step of detectingthe defect, the signals outputted in parallel from the TDI sensor areprocessed in parallel.